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T. A. EDISON v I FIXTURE AND ATTACHMENT FOR ELECTRIC- LAMPS.

No. 248,420. Patented 0t "Ill-Iii lLlL aaw P611 N. PETERS,Phaflrlilhngrapher. Waihmglon. 0. cv

NITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEIV JERSEY, ASSIGNOR TO THE EDISONELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.

FIXTURE AND ATTACHMENT FOR ELECTRIC LAMPS.

SPECIFICATION forming part Of Letters Patent NO. 248,420, dated October18, 1881,

ApplicationfiledMarchQG, 1 881. (NomodeL) To all whom it may concern Beit known that I, THOMAS A EDISON, of Menlo Park, in the county ofMiddlesex and State of New Jersey, have invented a new and 5 usefulImprovement in Fixtures and Attachments for Electric Lamps; and I dohereby declare that the following is a full and exact description of thesame, reference being had to the accompanying drawings, and to theletters of reference marked thereon.

In a system of electric lighting such as I have shown, wherein the lampsare intended to normally give only the volume of light of a standardsixteen-candle power gas-jet, it is desirable that fittings for carryingand supporting the lamps should be devised as nearly resembling thosewhich experience has shown to be most desirable in gas-lighting as thedifferences in the lighting agents will admit.

One of the most useful devices in gas-light- ----,.ing systemsis theswinging bracket, as it gives adegree of adjustability to the positionof the light. Where it has been attempted for any purpose to run anelectric circuit through such a fixture in such manner that the circuitshould be preserved in any relative position of the arms of the bracketor of a single arm to its base the connections for such purpose havebeen exposed. Such an arrangementis defect- 3oive in that there isdanger of accidental connection or short-circuiting, and liability todeterioration of electrical contact from dust and dirt settling upon thecontact-surfaces.

One object of this invention, therefore, is to provide a swinging orhinged bracket-arm for carrying and supporting an electric lamp,arranged to preserve the electric circuit in any relative position ofthe arms to each other, and of an arm to the base, and in which theconnections are incased, so as to be preserved from danger of accidentalelectrical connection, and so as to be protected from dust or dirt. ThisI accomplish as follows: One of the arms is provided with a box or caseof suitable size at its end, in which the pivot proper is to turn. Tothe other arm is secured the pivot, made of insulating material, uponwhich are secured two separate metal bands orrings, which form theterminals of the conductors passing through this arm. The pivot passesinto the interior of the box or case on the other arm through anaperture in its top, the sides of the aperture forming a bearing for thepivot, the bottom of the pivot resting upon the bottom of the box orcase, and there secured by a screw passing 5 5 through the bottom of thebox into it and forming a center upon which it may turn. The conductorsin the arm carrying the box pass through. the arm into the box andterminate therein, each in a spring, the two springs being insulatedfrom each other and secured at one end to the interior of the box, fromwhich they are also insulated, their other ends bearing upon the metalbands or rings of the pivot, one on each. As each spring then bears uponits ring or hand during the entire rotation of the arm it is evidentthat the circuit is always completed from one arm to the other,irrespective of their relative positions, and so an electrical lampbracket is made possible. The bracket may consist of any number of sucharms, pivoted together in like manner. Instead of springs within the boxan insulatin g cylinder with interior metal rings arranged to coincidewith the rings upon the pivot may be used, or the box itself may be ofinsulating material, with such rings in its pivotal cavities, or to aninsulated pivot or spindle springs may be fixed to bear upon rings uponthe interior of an insulated cylinder or pivotreceptacle, or one ringand one'spring may be used, a single conductor passing through thebracket, the metal of the bracket and system of pipes being used for theother conductor;

but such modifications would only be equivalents of the springs andrings, as described.

Instead of having acircuit-controller located upon the fixed support ofthe bracket, as is the gas-cock upon a gas-light bracket, it may bepreferable to have it at thelamp itself. In such case a projecting keyor circuit-controller such as I have shown in other applications wouldbein danger of accidental displacement or breakage. v

One object of this invention is to provide a circuit-controller whichshall have no projecting parts, and in which all the electricalconnections are so placed as to be protected and to be free from alldanger of accidental displacement or contact. To this end acircuitcontroller is made in which the movable part accessible to theuser is simply a plain band or ring of insulating material.

A socket for thelamp is used, such as I have shown in otherapplications, consisting of a piece ofinsulating material hollowed outfrom the top and provided at its base with means for its attachment to apipe, bracket, or chandelier arm. Upon the interior of the socket aretwo metal rings or hands or plates, forming terminals of the conductorsleading through the pipe or otherwise to the socket. Upon the neck orbase of the lamp are two rings, sockets, or plates forming terminals tothe conductors leading from the incandescing conductor of the lamp, andso arranged that they coincide with the rings, bands, or plates of thesocket when the lamp is placed therein, so that the circuit iscompleted, except as modified by the circuit-controller by the act ofplacing the lamp in its socket. The conductor leading to one of therings, bands, or plates of the socket is interrupted or broken, theconductor leading to a pin upon the exterior of the socket, while asecond pin is placed above'and contiguous thereto, which is connected toone of the rings, bands, or plates of the socket. The socket isshouldered upon the exterior, and upon this shoulder rests a ring ofinsulating material larger than the part of the socket it incloses, butwith a flange extending inwardly at the top, so as to approach closelythe upper part, a chamber being formed thereby, the socket forming itsinner wall, the shoulder its base, and the flangeits top. Upon theinterior of this ring is fixed a wedge which may be solid, but which ispreferably made ofa springy piece of metal bent back upon itself, and ofsuch size that its extreme edges contact with and close circuit betweenthe two pins before noted.

Upon the socket within the ring a springpawl may be fastened, takinginto recesses out upon the interior of the ring, so as to limit themovement of the ring upon the socket and also indicate by the click ofthe pawl passing into a recess when the necessary amount of movement hasbeen given; or a screw may pass through the ring and play in a slot inthe socket, or vice versa, to determine the movement which may be giventhe socket. By this arrangement a reliable circuit-controller isfurnished, which may be placed at the lamp itself or in exposedsituations without danger of accidental manipulation or breakage. Thesevarious arrangements are clearly illustrated in the drawings, in which-Figure 1 is a view of the socket and controller in section and of thebase or neck of the lamp in elevation; Fig. 2, aviewofa bracket-arm,partly in section, with socket thereon, the movable circuit-controllerring being removed therefrom, while Fig. 3 shows the removed ring inperspective, and Fig. 4 shows the pivot, rings, and springs.

A F, Fig. 2, are two arms of a bracket, of which A supports at its outerend the lampsocket C, while at its inner end there is secured to it thepivot K, of insulating material, upon which are the metal bands or ringsu 'v, the cond nctor 7 being attached to u, and 8 to v. This pivot isplaced and rotates in a box or casing, L, upon the end of the arm F,being secured thereto by a screw, M, passing through the bottom of thebox or easing into the pivot K, the screw M serving as a center ofmotion therefor.

To the interior of the box are secured, insulated from it and eachother, the springs H G,

to which are secured the conductors 1 2, as I shown, 1 to G and 2 to H.This relation of the springs and rings is clearly shown in Fig. 4. It isevident from this that 1 G u 7 are always electrically connected, andthat so are 2 H v 8, no matter what the relative positions of A and Fmay be. It is evident, also, that as many arms as desired may beconnected in this way, and that they may be connected to work at rightangles, so that thelamps may be placed in any desired position withinthe limits of the net length of the bracket-arms. It is also evi dentthat the modifications and changes hereinbefore noted may be madewithout departing from the spirit of this portion of the invention.

E is the base or neck of the lamp L, (partly shown,)ofinsulatingmaterial,and havingupon it the metal plates as y, to which areconnected, respectively, the conductors 3 4, leading to the incandescingconductor. Of these y is formed into a screw-thread to engage with 11upon the interior of the socket C, so that the lamp willbepositivelyheld therein. Oneofthemainconductors, 8, leads and isconnected to d, so that when the lamp is in position one portion of thecircuit is completed via 8 d y 4.

The socket is formed with a shoulder, W,extending out from it, as seenin Figs. 1 and 2. Upon the exteriorof the socket, and one above theother, are two pins,a b, the main conductor 7 leading and connected toI), while a is connected to the plate f within the socket, with which wcontacts when the lamp is in position upon the socket. Upon the shoulderis placed a ring, B, having at its top an inwardly-extending flange, 0,closing round the top of socket, a chamber being left between the flangeo and shoulder w. Upon the interior of the ring is secured a wedge, n,(seen in Fig. 3,) which may be solid metal,but which is preferably, asshown, made of a strip of springy metal bent back upon itself, and of asize to fill the space between a and b and make contact with both whenforced between them.

To determine the movement of the ring B and to hold it from coming off ascrew, 12, passes therethrough and plays in a slot or recess,p, cut inthe side of C.

If desired to indicate audibly when the proper amountof movement hasbeen given B, aspringpawl, c, with beveled or wedge-shaped end,

I may be attached to G, and corresponding recesses 0 cut in the interiorof B at proper points, whereby the movement of B would be limited,aswell as an audible indication given.

As before stated, when the lamp is in position the connection 8 d3 4 iscomplete,but the connection 7 b a f a0 3 is broken between a and b. It,now, the ring B be turned in the proper direction, (and from thelimiting action of p p or of c c, if the latter be used,it can be turnedin no other direction,) the spring-wedge n is carried between the pins aI), electrically connecting them and completing the connections 7 b af4v 3,while movement in the other direction removes the spring-wedge frombetween them and breaks the circuit.

As the manipulative part of the circuit-controller is a simple ring, B,with no projecting parts to receive a blow or to catch upon orbe caughtby anything, there is no danger of accidental operation ordisarrangement of the circuit-controller.

What I claim is- 1. The combination of two bracket-arms, and a pivotalconnection therefor, arranged to constantly maintain electricalconnection from a conductor in one arm to a conductor in the other, anda casing attached to one arm and inclosing and protecting the pivotalconnection, substantially as set forth.

2. The combination of two bracket-arms,one pivoted upon or within theother so as to rotate freely, and means, substantially as described, forconstantly maintaining electrical connection between a conductor orconductors in each arm, and a casing attached to one arm and inclosingand protecting the pivotal connection, substantially as set forth.

3. The combination of a bracket arm provided with an insulated pivotalpiece having thereon one or more metal rings, and a bracketarm having abox or casing to receive the pivotal piece, and provided with a springor springs constantly bearing upon the ring or rings, and

electrical con nectionsfrom the spring or springs and ring or rings, anda casing inclosing and protecting the springs and rings, all arrangedsubstantially as set forth.

4. A swinging electrical-lamp bracket composed of two or more armsprovided with means for constantly maintaining the proper electricalconnections therethrcugh, and a casing inclosing and protecting the saidmeans, substantially as set forth.

5. A circuit-controller for an electric lamp in which the manipulativeportion is a band or ring of insulating material mounted directly uponthe lamp-socket, substantially as set forth.

6. The combination, with a broken electrical circuit, of acircuit-closer attached to the interior of a band or ring of insulatingmaterial mounted upon the base of the lamp, substantially as set forth.

7. The combination, with the socket of an electric lamp, of acircuit-controller operated by a ring or band of insulating materialencircling the socket, substantially as set forth.

8. The combination,with an electric circuit,

of two pins,whereat the circuit is broken,and*

a wedge for closing such break, attached to the interior of a bandencircling and hiding the pins and circuit-connections, substantially asset forth.

9. The combination, with a circular or ring circuit-controller, of meansfor limiting its mot-ion, substantially as set forth.

10. The combination, with a circular or ring circuit-controller, ofmeans for audibly indicating when the proper amount of movement has beengiven, substantially as set forth.

This specification signed and witnessed this 7th day of March, 1881.

' TElOS. A. EDISON. Witnesses:

H. W. SEELY, S. D. MOTT.

